The present invention relates to a method for assembly and testing the insulation of electronic power components in electrical switching and control devices.
More particularly, it relates to a method for assembly and testing the insulation of such control devices, particularly for motor vehicles which are fastened to a heat sink so as to be thermally conducting and electrically insulating, which heat sink fits securely on a printed circuit board on which the power components and additional electrical component elements are connected via conductor path by soldering together with connection parts and a circuit ground.
It is already known from DE-OS 33 31 207 to fasten the electronic power components at a heat sink via a thermally conducting insulating foil by means of a plastic fastening part and to perform electrical testing of the component group preassembled in this way. High voltage is applied for testing the insulation between the heat sink and power components. The preassembled component group is then fastened on the printed circuit board and the connection pins of the power components must be inserted into the holes of the printed circuit board assigned to them in a costly and cumbersome manner. The power components are then connected with additional electronic component elements on the printed circuit board by soldering. In such switching and control devices for motor vehicles the component elements on the printed circuit board generally form a logic and the power components form the end stages in the form of power transistors.
The aforementioned method for assembly and testing the insulation between the heat sink and power components is supposed to ensure that sensitive component parts, e.g. computers, on the printed circuit board are not destroyed by high voltage. However, the known solution has the disadvantage that the insertion of the preassembled heat sink and power component group into the printed circuit board poses considerable problems, particularly with bent connection pins, so that mechanical assembly is not possible.